1 With API and ISO9001 2 High quality and competitive price 3 Various of model ... bit1.High-strength, high flexibility, high temperature, high wear resistance.2. High-precision metal seal.3. Locking roller ball, to ... We are looking forward to your early reply. Thank you for attention me ! sizebit typein.mm6152.4136,127,517,537,617 ... ,537,617,63726660.4114,517,537,617,637 75mm opening bearing tricone bit